The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes from Ancient Greek σπλήν (splḗn).
Waterhouse–Friderichsen syndrome (WFS) is defined as adrenal gland failure due to bleeding into the adrenal glands, commonly caused by severe bacterial infection. Typically, it is caused by Neisseria meningitidis.
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets (thrombocytes) and fibrin to form a blood clot to prevent blood loss. Even when a blood vessel is not injured, blood clots may form in the body under certain conditions. A clot, or a piece of the clot, that breaks free and begins to travel around the body is known as an embolus.
A splenectomy is the surgical procedure that partially or completely removes the spleen. The spleen is an important organ in regard to immunological function due to its ability to efficiently destroy encapsulated bacteria. Therefore, removal of the spleen runs the risk of overwhelming post-splenectomy infection, a medical emergency and rapidly fatal disease caused by the inability of the body's immune system to properly fight infection following splenectomy or asplenia.
Hereditary spherocytosis (HS) is a congenital hemolytic disorder, wherein a genetic mutation coding for a structural membrane protein phenotype leads to a spherical shaping of erythrocytic cellular morphology. As erythrocytes are sphere-shaped (spherocytosis), rather than the normal biconcave disk-shaped, their morphology interferes with these cells' abilities to be flexible during circulation throughout the entirety of the body - arteries, arterioles, capillaries, venules, veins, and organs. This difference in shape also makes the red blood cells more prone to rupture under osmotic and/or mechanical stress. Cells with these dysfunctional proteins are degraded in the spleen, which leads to a shortage of erythrocytes resulting in hemolytic anemia.
Asplenia refers to the absence of normal spleen function and is associated with some serious infection risks. Hyposplenism is used to describe reduced ('hypo-') splenic functioning, but not as severely affected as with asplenism.
Splenomegaly is an enlargement of the spleen. The spleen usually lies in the left upper quadrant (LUQ) of the human abdomen. Splenomegaly is one of the four cardinal signs of hypersplenism which include: some reduction in number of circulating blood cells affecting granulocytes, erythrocytes or platelets in any combination; a compensatory proliferative response in the bone marrow; and the potential for correction of these abnormalities by splenectomy. Splenomegaly is usually associated with increased workload, which suggests that it is a response to hyperfunction. It is therefore not surprising that splenomegaly is associated with any disease process that involves abnormal red blood cells being destroyed in the spleen. Other common causes include congestion due to portal hypertension and infiltration by leukemias and lymphomas. Thus, the finding of an enlarged spleen, along with caput medusae, is an important sign of portal hypertension.
An autosplenectomy is a negative outcome of disease and occurs when a disease damages the spleen to such an extent that it becomes shrunken and non-functional. The spleen is an important immunological organ that acts as a filter for red blood cells, triggers phagocytosis of invaders, and mounts an immunological response when necessary. Lack of a spleen, called asplenia, can occur by autosplenectomy or the surgical counterpart, splenectomy. Asplenia can increase susceptibility to infection. Autosplenectomy can occur in cases of sickle-cell disease where the misshapen cells block blood flow to the spleen, causing scarring and eventual atrophy of the organ. Autosplenectomy is a rare condition that is linked to certain diseases but is not a common occurrence. It is also seen in systemic lupus erythematosus (SLE).
Primary myelofibrosis (PMF) is a rare bone marrow blood cancer. It is classified by the World Health Organization (WHO) as a type of myeloproliferative neoplasm, a group of cancers in which there is activation and growth of mutated cells in the bone marrow. This is most often associated with a somatic mutation in the JAK2, CALR, or MPL genes. In PMF, the bony aspects of bone marrow are remodeled in a process called osteosclerosis; in addition, fibroblast secrete collagen and reticulin proteins that are collectively referred to as (fibrosis). These two pathological processes compromise the normal function of bone marrow resulting in decreased production of blood cells such as erythrocytes, granulocytes and megakaryocytes, the latter cells responsible for the production of platelets.
In human anatomy, the splenic vein is a blood vessel that drains blood from the spleen, the stomach fundus and part of the pancreas. It is part of the hepatic portal system.
A splenic injury, which includes a ruptured spleen, is any injury to the spleen. The rupture of a normal spleen can be caused by trauma, such as a traffic collision.
Portal vein thrombosis (PVT) is a vascular disease of the liver that occurs when a blood clot occurs in the hepatic portal vein, which can lead to increased pressure in the portal vein system and reduced blood supply to the liver. The mortality rate is approximately 1 in 10.
Felty's syndrome (FS), also called Felty syndrome, is a rare autoimmune disease characterized by the triad of rheumatoid arthritis, enlargement of the spleen and low neutrophil count. The condition is more common in those aged 50–70 years, specifically more prevalent in females than males, and more so in Caucasians than those of African descent. It is a deforming disease that causes many complications for the individual.
Hemosuccus pancreaticus is a rare cause of hemorrhage in the gastrointestinal tract. It is caused by a bleeding source in the pancreas, pancreatic duct, or structures adjacent to the pancreas, such as the splenic artery, that bleed into the pancreatic duct, which is connected with the bowel at the duodenum, the first part of the small intestine. Patients with hemosuccus may develop symptoms of gastrointestinal hemorrhage, such as blood in the stools, maroon stools, or melena, which is a dark, tarry stool caused by digestion of red blood cells. They may also develop abdominal pain. It is associated with pancreatitis, pancreatic cancer and aneurysms of the splenic artery. Hemosuccus may be identified with endoscopy (esophagogastroduodenoscopy), where fresh blood may be seen from the pancreatic duct. Alternatively, angiography may be used to inject the celiac axis to determine the blood vessel that is bleeding. This may also be used to treat hemosuccus, as embolization of the end vessel may terminate the hemorrhage. However, a distal pancreatectomy—surgery to remove of the tail of the pancreas—may be required to stop the hemorrhage.
Spleen transplantation is the transfer of spleen or its fragments from one individual to another. It is under research for induction of immunological tolerance for other transplanted organs. Success has been achieved in rodent models. Recently, evidence has been obtained for a tolerogenic effect of a spleen transplant in miniature swine. Also, the spleen harbors primitive hematopoietic progenitor cells. Spleen transplantation has been performed on humans with mixed results.
Wandering spleen is a rare medical disease caused by the loss or weakening of the ligaments that help to hold the spleen stationary.
Blunt splenic trauma occurs when a significant impact to the spleen from some outside source damages or ruptures the spleen. Treatment varies depending on severity, but often consists of embolism or splenectomy.
Juvenile myelomonocytic leukemia (JMML) is a rare form of chronic leukemia that affects children, commonly those aged four and younger. The name JMML now encompasses all diagnoses formerly referred to as juvenile chronic myeloid leukemia (JCML), chronic myelomonocytic leukemia of infancy, and infantile monosomy 7 syndrome. The average age of patients at diagnosis is two (2) years old. The World Health Organization has included JMML as a subcategory of myelodysplastic and myeloproliferative disorders.
Cold autoimmune hemolytic anemia caused by cold-reacting antibodies. Autoantibodies that bind to the erythrocyte membrane leading to premature erythrocyte destruction (hemolysis) characterize autoimmune hemolytic anemia.
Spleen pain is a pain felt from the left upper quadrant of the abdomen or epigastrium where the human spleen is located or neighboring.
